Why Lower Don Flood Protection is a Necessary Cost

The projected cost to protect the 356-hectare Port Lands rose to $1.25 billion last month, part of the massive Waterfront Toronto-led revitalization of the largely industrial lands east of downtown Toronto.

While developing the city’s lakeshore with a host of recreational, industrial, residential, and retail opportunities has taken centre stage in the agency’s efforts to improve Toronto’s strained relationship with its waterfront, protecting large swaths of land from the devastating impacts of flooding has always been a crucial (if subtle) cornerstone of the plan.

But a due diligence report released on October 20 by Waterfront Toronto suggested that more than 283 hectares in the Port Lands, Riverside, Leslieville, and the Unilever site are at risk of flooding from the nearby Don River. What’s more, the land cannot be developed until proper protections are put in place, they argue.

A previous cost estimate put the protection work at $975 million, an estimate that was “less informed” than the latest projection, Waterfront Toronto writes. Now, the agency says the discovery of “flowing sand” and “compressed peat” in the area will require additional environmental risk measures, enhanced erosion control, and previously unaccounted for groundwater and soil treatment.

The new $1.25 billion figure also includes a 30 per cent contingency. Construction, believed to take seven years, could begin in 2017.

“Based on Waterfront Toronto’s experience working on waterfront projects and the poor underground conditions, contaminated soil and high water table that characterize the area, we knew that flood protecting the Port Lands will be challenging,” said Waterfront Toronto Chief Operating Officer David Kusturin in a release. “We wanted to provide as much assurance as possible to governments on what this project would cost, how long it would take to build and the nature of the project’s risks.”

Hazel’s Legacy

No story of flood protection’s human scale in Toronto is complete without a basic understanding of Hurricane Hazel’s devastating impact on the city. It struck in October 1954. Previous fall rains had saturated the soil, leaving nowhere for storm water to go. Steep ravines funnelled rain into rivers that flowed up to four-times faster and higher than normal. Roads, bridges, houses—sometimes entire streets—were washed out in Etobicoke and Toronto, particularly near the Humber and Don rivers. Eighty-one people died.

Yet Toronto’s history with severe flooding extends well beyond Hazel. Flooding in the Greater Toronto Area as we know it was first written into the city’s records in 1797 and remained a recurring problem throughout the 19th century. Calls for greater flood protection that got louder in Hazel’s aftermath actually began in 1878 when five inches of rain fell in seven hours, inundating downtown Brampton and washing out bridges, houses, mills, and dams.

Flooding in a city as relatively unscathed from natural disasters as Toronto seems like an abstract problem only until the calamity is upon us. City residents and government agencies alike were caught off guard in July 2013 when five inches of rain fell in two hours, more precipitation in that 120 minute stretch than the city typically sees in the entire month. GO Trains in the Don Valley sat immovable on submerged tracks as drivers on the adjacent highway abandoned vehicles buried engine-deep in turbid floodwater. With its $850 million price tag, this single downpour became the costliest natural disaster in Ontario’s history. (For comparison’s sake, damages from Hurricane Hazel cost an estimated $226 million in today’s dollars.)

And despite regulatory changes in the aftermath of extreme weather events like Hurricane Hazel—when the City expropriated over 2,900 hectares of ravine land in private hands at a cost of $105 million today to safeguard against human lives lost to future flooding—some parts of the Greater Toronto Area remain vulnerable to rising rivers.

According to the Toronto and Region Conservation Authority, the GTA contains 42 “flood vulnerable” areas from central Brampton and Long Branch in the west to Stouffville and Carruthers Creek in the north and east. “We have a lot of structures that were built before policies that limited the amount of development within the floodplain,” Laurian Farrell, manager of flood risk management at TRCA, told Global News after the 2013 flood. City governments aren’t prepared to start expropriating land or demolishing houses as they did after Hurricane Hazel, Farrell said, but we need to manage these hot spots more closely.

Looking Ahead

That’s what the Port Lands project aims to do as one of the largest long-term components of the entire lakeshore revitalization. Central to the plan from day one has been nothing less than creating an entirely new mouth for the Don River for flood prevention and climate change mitigation purposes. When finished, the Don will flow in a naturalized, meandering path surrounded by parkland—a stark contrast to the concrete elbow and litter-blocking yellow booms currently welcoming the river to the lake. It’s a long overdue facelift for the city’s most iconic (and abused) river.

Since Hurricane Hazel jolted the city and provincial governments into taking flood protection seriously, comprehensive watershed management plans covering the entirety of the GTA have been implemented. Conservation authorities were formed to oversee what’s become a massive public infrastructure project. Culverts, dams, dykes, and hundreds of minor control points have been established to regulate the flow of floodwater in Toronto on more than 32,000 acres of land controlled by the TRCA for expressly that purpose.

But flood control isn’t a project in Toronto’s rear-view mirror. Weeks before the city was deluged in July 2013, Corktown Common opened to the general public. Situated near the mouth of the Don River on the west bank, this green space—replete with a children’s playground, BBQs, and a splash pad—also serves as flood protection for downtown and the people who live and work from the Canary District as far west as Bay Street. At a cost of $135 million, what looks like rolling hills of prairie grasses and saplings is actually part of an 8.5 metre-high berm that sweeps floodwater toward Lake Ontario. It’s engineering built into the city’s natural fabric.

The anticipated value of the Port Lands investment, like Corktown Common, is impressive. In their latest report on the Port Lands project, Waterfront Toronto argued that construction and future development in the region will add $5.1 billion to the Canadian economy and a further $1.9 billion in government revenues. Yet none of this is possible without the upfront investment needed to secure the Port Lands and surrounding area from future flooding. “Investing strategically in the Project not only unlocks development value and protects existing neighbourhoods,” the report states, “but also protects governments from significant financial risk.”

Protecting Canada’s largest city from the ravages of flooding and other extreme weather events isn’t cheap. But, as every disaster from Hurricane Hazel to the July 2013 flooding has attested, neither are the costs of cleanup or the damages inflicted on public and private property—not to mention the threat such events pose to humans and wildlife. And as extreme weather events occur with more regularity as a result of climate change, Toronto may be discovering that the increasing cost of flood protection is simply the new cost of doing business as an urban centre in a warming world.